Had many noisy gearboxes apart. The normal failure mode is that the large nut on the end of the pinion shaft loosens up, as the original locking mechanism is weak. This wreaks all kinds of havoc, including the shaft drilling into the rear cover plate. The engagement of the pinion becomes loose to the point that it can go kerblammo. Before that, lots and lots of metal filings swirl around and cause rapid bearing wear creating additional noise.

One quick way to know if the pinion nut is loose, is to drive in freewheel mode at say 50 mph. Look at the speedo and take your foot off the gas. The amount it drops is indicative of the looseness of the nut. 5mph and you got trouble. 10mph and you got BIG trouble.

That's a start anyway.

eric in vermont

->Posting last edited on Tue, 7 Nov 2017 15:08:51.Posts in this Thread:

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